Tuesday 29 May 2012 09.36 EDT
First published on Tuesday 29 May 2012 09.36 EDT

Despite renewed complaints over their unwieldy ticketing system, London 2012 organisers have sold tens of thousands more tickets to the Games and claimed vindication over their decision to charge for sections of the road cycling races.

Meanwhile, Paralympics officials expressed confidence the London Games could become the first to completely sell out in the event's 52-year history, following another round of strong ticket sales.

Among the tickets that went on sale for the first time on Tuesday were 25,000 for the climbing section of the cycling road race at Box Hill and the cycling time trial at Hampton Court.

Cycling fans are used to watching their heroes for nothing, but Locog said the men's events had sold out in a single day.

Initial demand meant the much-criticised Ticketmaster system again slowed to a crawl, amid a deluge of interest.

"The sheer volume of demand meant that we managed transactions slowly in the first 20 minutes. However transactions are now flowing through in their thousands," said a spokeswoman.

Timed tickets to ascend the Orbit sculpture in the Olympic Park also went on sale for the first time. In all, around 450,000 tickets to the Games remain – plus 1.3m football tickets that are expected to prove difficult to shift.

More than 1.2m of the 2.2m tickets on offer for the 2012 Paralympics, which run from 29 August to 9 September, have already been sold, the bulk of them in a much-promoted initial sales window in September. Another 125,000 were sold last week, the highest total in a single seven-day period to date.

"We're probably in the strongest position we've ever been in for ticket sales ahead of a Paralympics," said Craig Spence, head of communications for the Bonn-based International Paralympic Committee. "It would be great if we could sell out the Games. It's definitely possible; there's a real potential for us to do it.

"It would be amazing. Bear in mind that in Sydney 12 years ago they were still giving away a lot of tickets. Tickets being sold for a Paralympic Games is still a fairly new thing, so to sell all of them for full price would be pretty remarkable."

Adrian Bassett from Locog, which is responsible for the ticket sales, said the scale of early sales had been unprecedented: "A sellout is certainly possible. When you look at previous Paralympics it's quite often during the Olympics or just before that people wake up to the Paralympic Games, and there's a surge of ticket sales then. We're expecting to still be selling tickets quite close to the Games themselves."

Even if the Games opened with just a few seats unsold, it would be a big achievement, both for the London Games and the wider acceptance of Paralympic sport.

At most of the 15 summer Paralympics since the first, in Rome in 1960, seats have been given away. The 2000 Sydney Games sold 1.2m; Athens, four years later, 850,000. More than 3.6 million people watched Paralympic events in Beijing in 2008, but almost half the tickets were given away to schools and community groups. Even the 1.82m full-price tickets were relatively cheap, ranging from 30 to 80 yuan (about £3 to £8).

The London Paralympic prices remain competitive – aside from the opening and closing ceremony, the highest figure is £45, while 75% cost £20 or less

The interest in tickets has been prompted by a number of factors, Spence said, ranging from pre-Games coverage by Channel 4, which will broadcast the Paralympics, to the wider awareness of Paralympic sports inthe UK. He said: "People are buying into the concept. British Paralympic athletes are far more well known, say compared to China. We're in a far stronger starting position here than we were going into the Beijing Games. Paralympic sport is probably more accepted in this country than in any other country in the world."Interest has also been spurred by the likelihood of some home success: the British team won 42 golds in Beijing, and has come second in the medal table in the last three s